中文摘要：

通过设计特定声调组合和语境的实验室语句,考察了韵律短语边界对语句中降阶和焦点后音高骤降的影响规律,以及降阶和焦点的作用域。结果发现,在由两个韵律短语组成的语句中,韵律短语边界会阻断前一短语中的降阶作用,降阶的作用域是韵律短语。焦点的实现与降阶不同：焦点后的正向音高降低作用会跨越韵律短语边界,使得后一韵律短语的高音线明显降低;如果后一韵律短语中有降阶,则焦点的跨边界音高降低作用会与降阶作用累积在一起,产生更低的高音线,说明焦点的作用域是语调短语。但当后一韵律短语也出现焦点时,音高重置阻断了前一短语中焦点的正向音高降低作用,此时两个焦点分别独立地实现。

英文摘要：

The effects of prosodic phrase （PP） boundary on the pitch lowering of downstep and focus, as well as the domains of them were investigated in Chinese Putonghna, by using designed sentences which consist of two prosodic phrases （i.e., PP1, PP2）. The results showed that： （1） The PP boundary blocked the downstep effect in the preceding phrase, indicating that PP is the domain of downstep. （2） The post-focus F0 lowering effect in PP1 spread across the PP boundary and lower the F0 contour of PP2. If there is also a downstep effect in PP2, the postboundary compression effect of the prior focus will accumulate with the downstep, producing further lowered contour. Therefore, the domain of focus is an intonational phrase （IP）. （3） When there is one contrastive focus in each phrase, the outstanding pitch reset elicited by the second focus will block the F0 lowering effect of PP1 onto PP2, and the two loci are realized independently.